Hello everybody,

I think I could get more help in this forum. So please send me your comments. I've already received some valuable suggestions from SL forum buddies. Thanks. I have been reading your posts for few nights and I think I need to give you the exact picture so you can help me out better. Sorry to make it so long.

I just bought a 1992, 300SL, with only 62K miles. It is beatiful. I drove it home smooth and nice that night. Few days later I drove it for about 50 miles again at night with no problem. Finally I decided to take it work and just about 7 miles on a hot day engine started to sputter and stalled at the cross sectionwhen taking off from the stop light. I was able to strat the engine and make it to my work place parking lot few blocks away. This short run took few more starts. Then in the parking lot it started few more times and stalled every time shortly. I was able to go high RPM for very short time about few seconds each time but finally it died and didnt start again. After few hours the engine started normally. I didn't drive it and left it there untill I took off from work and drove it home at nihgt with no problem (7 miles). Few days later I drove it to grocary shop 3 miles away (around noon). After 15 to 20 minutes back from shopping the car did not start again. Did start couple times but stalled right away. Left it there and went back at night and drove it home with no problem. Yesterday I decided to take it to my friends house and check it out. It died few blocks away from home and was towed there. It started again after few hours and made it from drive way into the garage and died.

From my research here and your experiences with similar temperature related problems, I have narrowed it down to Crank Position Sensor, Fuel pump/fuel pump relay and OVP relay. But I need more help specific to my car make and model.

BTW, check engine light never comes up. Bulb is OK. So no codes.

Please advise. I make my next messages short. I promise.

Wiring harness is in very good condition. Distributor cap looks new.

Hey, sean19 did you install that crankshaft position sensor that you ordered?

The ignition coil is another possibility. In my experience their bad side surfaces when they get warm. Just another possibility.

Electric fuel pumps tend to bite after the car has been driven 15-20 mins or miles(depending on speed) and will not restart until the system has had a chance to cool off. That can be 30 min to an hour or more, depending on ambient temperature. From what I've read, your situation does not sound quite like this.

Someone in this thread asked about the crank position sensor - CPS. I do not know if it's resistance specs are listed at the following site, but you might check:

http://mb.braingears.com

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Hi,

The crank pos sensor is not here yet. They said it will arrive wednesday. I'm going to test the fuel pump tonight and listen to it if I can get the car to its bad side. Is there any way to check the coil?
Does any body know if my model has a stand alone fuel pump relay or it is one of the integrated ones?

Thanks for all your comments.

According to this sites parts facility, you have the following - integrated:

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1KU172UOY1UI03A8VX&year=1992&make=MB&model=300-SL-001&category=P&part=MAS+Control+Unit

This thread may help with testing the fuel pump relay circuit in this integrated unit:

300SE poor starting

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Thanks again Mike,
I couldn't get to the car tonight. It's sitting in my friend's garage since I don't have one. This is very inconvinient as I have plenty of time these days and I don't want to go there when she's not home.

I have to get it fixed by the end of the week or will have no choice to take it to MB dealer. Hate that. None of my cars have ever been to a mechanic shop. (except once for rebuilding engine on my 1977 VW Golf)

One of the site addresses didn't work. The other one discussing the fuel pump and relay was useful.

Now I have a list of items to be checked. Will keep you posted. Appreciate your help.

Mike, the address works fine now and I saw the photo and the part number of the MAS. Thanks.

I had that same problem with my car; turn out to be the fuel accumalater, by the gas filter.

I had to share this with you all before going to bed. Well since I didn't receive the CPS, I spent some time checking other possibilities this morning.

Today engine didn't start even cold without help from sparying into the intake. Then stayed running for few minutes until I pushed on the gas pedal and it died. Long story short: I started with opening the distributor cap which seemed brand new. Well it was not!! It had a good amount of depotits on each pole inside the cap. More than what I had ever seen before. There was a layer of moisture inside. Very thick and visible. I'm not sure if it was water or oil. I should have paid more attention before I wiped it off.

Cleaned, washed and dried in sun and put it back. Guess what? Problem is gone. It started over and over, cold or warm. I let it run for about 20 minutes. Turned off and acranked again in betweem so many times every time started and idled smoothly. Drove it to work in a warm outside temperature and came back after work at night. No problem or any signs of it.

Thank you all specially Mike for valuable comments. I have other issues which I will post soon. Not so serious though.

I think I will change the distributor cap, seal, and rotor anyways. So far so good.

I need to check later if it was oil in the cap wether it accumulates again over time or not.

Thanks again.
Sean

SL300 1992
VW Cabrio 2001
VW Beetle 1968